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Process for producing acrolein and/or acrylic acid

a technology of acrylic acid and acrolein, which is applied in the preparation of carbonyl compounds, carbonyl compounds, oxygen-containing compounds, etc., can solve the problems of unsatisfactory processes and the price of starting gas, and achieve the effects of suppressing the catalytic activity during steady-state operation, high efficiency, and high temperature reaction

Active Publication Date: 2011-01-20
NIPPON SHOKUBAI CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0009]Thus, according to the present invention, it is made possible to control the reduction in catalytic performance with time and to produce the object product continuously in high yield over a long period, in the production of acrolen and / or acrylic acid by catalytic gas-phase oxidation of propylene or a propylene-containing gas with molecular oxygen or a molecular oxygen-containing gas; or in the production of acrylic acid by catalytic gas-phase oxidation of acrolein or an acrolein-containing gas with molecular oxygen or a molecular oxygen-containing gas; in particular, in the production of acrylic acid by two-stage catalytic gas-phase oxidation of propylene or a propylene-containing gas with molecular oxygen or a molecular oxygen-containing gas.
[0011]According to the invention, in the occasion of catalytic gas-phase oxidation on an industrial scale, the initial stage operation is run from the start-up under a reaction temperature advancedly elevated higher than that for steady state operation, and thereafter the reaction temperature is lowered for running the steady state operation. This enables activation of the catalyst disposed at the gas-inlet site with high efficiency, which results in high performance of the catalyst at the gas-inlet site and suppression of its deterioration during the subsequent steady state operation under the lowered temperature, leading to production of the object product stably in a high yield over a long period. More specifically, for example, the term during which the conversion of the starting material such as propylene or acrolein is maintained at the target level can be extended when, for example, the steady state operation is carried out under a constant reaction temperature. Whereas, when the steady state operation is run under gradually or stagewisely elevated reaction temperature to maintain a prescribed conversion of the starting material, the temperature rise rate can be slowed down, leading to an extension of the period for the reaction temperature to reach the upper limit as set in the process.

Problems solved by technology

Still in addition, price of its starting gas is rising drastically.
Thus, economically the processes are not yet fully satisfactory.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[Preparation of the Catalyst]

[0033]In 2200 parts of distilled water, 350 parts of ammonium molybdate was dissolved under heating and stirring (solution A). Separately, 207 parts of cobalt nitrate and 86.5 parts of nickel nitrate were dissolved in 600 parts of distilled water (solution B). Also separately, 73.4 parts of ferric nitrate and 104 parts of bismuth nitrate were dissolved in an acidic solution formed by adding 25 parts of conc. nitric acid (65 mass %) to 350 parts of distilled water (solution C). These nitrate solutions (solutions B and C) were added to solution A dropwise, and successively 1.34 parts of potassium nitrate was added. Further adding 24.1 parts of antimony trioxide and 42.1 parts of alumina, a suspension was obtained. The resulting suspension was evaporated to dryness under heating and stirring to form a solid cake, which was dried at 200° C. and pulverized to not greater than 150 μm in size to provide a catalyst powder. Into a tumbling granulator 1350 parts o...

example 2

[Preparation of the Catalyst]

[0039]In 3000 parts of distilled water, 500 parts of ammonium paramolybdate, 82.8 parts of ammonium metavanadate and 95.6 parts of ammonium paratungstate were dissolved under heating and stirring. Separately, 85.5 parts of copper nitrate and 41.2 parts of cobalt nitrate were dissolved in 300 parts of water under heating and stirring. The resulting two aqueous solutions were mixed, and to which 27.5 parts of antimony trioxide and 24.5 parts of titanium dioxide were added to form a suspension. The suspension was heated under stirring and evaporated, and the resulting evaporation residue was dried at 240° C., followed by pulverization to not greater than 150 μm is size to provide a catalyst powder. Into a centrifugal flow coating apparatus, 1605 parts of spherical silica-alumina carrier of 5.0 mm in average particle diameter was added, and then the catalyst powder together with 20 mass % aqueous glycerin solution as the binder were slowly fed into the appar...

example 3

[Reactor]

[0044]Into a fixed bed shell-and-tube type reactor composed of approximately 9,500 reaction tubes (each having an inner diameter of 25 mm and a length of 6,000 mm) and a shell for passing a heating medium therethrough and for covering the reaction tubes, catalyst 2, catalyst 1, SUS Raschig rings each having an outer diameter of 8 mm, catalyst 4 and catalyst 3 were dropped from the top of each of the reaction tubes by the order stated, making the lengths of respective layers as follows: catalyst 2, 900 mm; catalyst 1, 2,000 mm; Raschig rings, 200 mm, catalyst 4, 700 mm; and catalyst 3, 2,200 mm. A 50 mm-thick partition plate to divide the shell into the upper and lower parts was installed at the position 3,000 mm from the bottom of the shell, and in both of the upper and lower shell spaces a heating medium was circulated upwards from the lower part. Hereafter the reaction zone loaded with catalysts 1 and 2 is referred to as the first reaction zone, and the reaction zone load...

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Abstract

In industrial scale production of acrolen and / or acrylic acid by catalytic gas-phase oxidation of propylene or a propylene-containing gas with molecular oxygen or a molecular oxygen-containing gas or in industrial scale production of acrylic acid by catalytic gas-phase oxidation of acrolein or an acrolein-containing gas with molecular oxygen or a molecular oxygen-containing gas, this invention provides a process characterized in that the initial stage operation is carried out under advancedly elevated reaction temperature and thereafter the reaction temperature is lowered to carry out the steady state operation. According to this process, acrolein and / or acrylic acid can be produced in high yield stably over prolonged period.

Description

TECHNICAL FIELD[0001]This invention relates to a process for producing acrolein and / or acrylic acid by catalytic gas-phase oxidation of propylene or a propylene-containing gas with molecular oxygen or a molecular oxygen-containing gas, or an improvement in a process for producing acrylic acid by catalytic gas-phase oxidation of acrolein or an acrolein-containing gas, with molecular oxygen or a molecular oxygen-containing gas.BACKGROUND ART[0002]Acrylic acid is industrially important as a starting material for various synthetic resins, paints, plasticizing agents and the like. In recent years, importance of acrylic acid particularly as a starting material of water absorbent resins gathers weight and the demand therefore tends to increase.[0003]For production of acrylic acid, new processes such as catalytic vapor-phase oxidation of the acrolein which is obtained through dehydration of glycerin from natural sources have been proposed in recent years. However, two-stage catalytic gas-ph...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): C07C53/12C07C27/12
CPCC07C45/35C07C51/252C07C47/22C07C57/04
Inventor TANIMOTO, MICHIOHAKOZAKI, NOBUYUKI
Owner NIPPON SHOKUBAI CO LTD
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